The AHA study is based on a survey of 164 doctoral-granting departments in the United States and Canada (out of 184 total such programs). The programs in the United States received an average of 80.9 applications for admission during the academic year that is ending now, up from 74.1 the previous year. Programs anticipated enrolling 9.2 new students this year, up from 9.1 a year earlier. Canadian programs saw a decline in the number of applications, but also anticipated a modest increase in the number of students matriculating.

While the increases may appear modest for this year, they represent a significant growth over the last decade. The AHA report notes that in the 1997-8 academic year, the same programs were enrolling an average of 5.5 new students.

Assuming that the average time to Ph.D. remains constant at the current eight years, the data suggest a significant increase in the supply of Ph.D.’s around 2015.

But as Robert H. Townsend, the AHA’s assistant director for research and publications, notes in the report on the data, there is a big question mark: program completion rates.

Departments are not uniform in when they consider someone to have left a program without a doctoral degree, and the varying patterns suggest that someone who may be considered to have dropped out in one program could be classified as still pursuing a degree in another. But by any measure, significant shares of those entering programs aren’t finishing. The AHA survey asked departments about the status of those who had enrolled 5 and 10 years earlier, and found that just under half (49 percent) had completed degrees after 10 years.

Completion rates were higher for Canadian programs -- 57 percent after 10 years.

Many departments and graduate programs are engaged in efforts to reduce attrition rates and time to degree -- so it is uncertain whether the students entering now will experience the same poor odds of completion. But Townsend notes that many clearly are not finishing up.

“The number of students reported as still pursuing the degree after 10 years seems quite large -- given that many programs publicly maintain a seven- or eight-year graduation requirement,” he writes. “This also begs the question of when and if the students still considered to be working on the degree after 10 years will ever finish their degrees.”